Isolation and characterization of the lymphocytosis-promoting factor (LPF) of B. pertussis has been achieved. The relationship between LPF, histamine sensitization, hypoglycemia and unresponsiveness to epinephrine will be explored as well as its effect on homocytropic antibody formation and activity. The mitogenic effect of LPF on T lymphocytes will be studied. The chemical nature and role of the hemagglutinating pili in the pathogenesis of whooping cough will be examined. Attempts will be made to isolate the component or product of B. pertussis responsible for tumor regression and to study its mode of action.